Shock strut



' July 19, 1938., FM. SMITH SHOCK STRUT Filed Nov. 1a, 1935 2Sheets-Sheet 1 mwswroa Smz'fk ATTORNEYEZ July 19, 1938.

M. SMITH SHOCK STRUT Filed Nov. 18,1935

2 sheets-sheet 2 INVENTOR.

A TTORNEYE.

PatentedJuly 19,1 93s 2,124,037.

UNITEDISTATES PATENT orrict SHOCK STRUT Frank M. Smith, Dear-born, Mich,assignor, by

mesne ts,. to Stout Motor Car Corporation, Dearborn, Micln, acorporation of Delaware Application November 18, 1935, Serial No. 50,302

- 8 claims. (on. 26'l20.) I

g This invention relates to shock struts. More. Still further, the.present invention contemparticularly, it relates to a shock strut whichis plates the provision of novel means for resiliently adapted for usein independent suspensions of limiting the telescoping movement of thememvehicle wheels. bers forming the strut with respect to each other. Itis a primary object of this invention to pro- This means may comprise aresilient cushion 5 vide a shock strut construction, the operation ofmounted on the terminal end'of one of the telewhich is not materiallyaffected by the subjecscoping members and annularly surrounding the tionthereto of substantial bending stresses. other member. A complementaiabutment is ar-.

Shock struts generally, comprise a pair of subranged and carried by oneof-the members l0 'stantially cylindrical telescoping tubular memadaptedto engage this resilient cushioning l0 hers. One of these members isgenerally atmeans in order to provide a resilient but eifectached to arigid support and the other attached tive limit to relative telescopingmovement of to a wheel or other element which is movably the members.mounted with respect to the support. Resilient Many other and furtherobjects and advanmeans are usually associated with the telescoptages ofthe present invention will become appari5 '30 paired.

ing tubular members in order that the relative ent from the followingspecification when conmovement thereof may be resiliently controlled.sidered in connection with the accompanying Shock struts of this generalcharacter have found drawings, forming a part thereof.

marked utility in the mounting of aeroplane the drawings, Y, wheels andin many other fields. Heretofore, Figure 1 illustrates an automotivevehicle of 20 it has been necessary, however, to use shock the typeparticularly adaptable for utilization of strutsof this general categoryonly in installashock struts of the present invention.

tions where the strut structureis effectually pro- Figure 2 is anenlarged fragmentary vertical I tected against any bending stresses, orany forces section taken on the line 2-4 of Figure 1, showother thanthose exerted axially of the telesccping the manner in which one of theimproved 25 ing members. Such transverse stresses have shock struts isused for resiliently mounting one been found to increase the frictionalengagement of the front wheels of the vehicle.

of the telescoping members to such an extent Figure 3 ls'a plan view ofthe wheel suspension that the operation of the strut is materially im- Iillustrated in Figure 2.

' Figure 4 is an enlarged detailed view partly in It is therefore thegeneral object of the pressection of a shock strut embodying theimproveent invention to provide a shock strut construcments' of thepresent invention. tion which will operate efficiently irrespective ofFigure 5 is a transverse sectional view taken A bending or transversestresses applied thereto. on the line 5-5 'of Figure 4 showing in detailThe shock strut of the present invention is, the telescoping arrangementof the various tubu- 35 due to its construction, particularly adapt-ablelar members making up the shock strut and the for use in independentsuspensions of veirfie mounting of one of the rollers therein. wheels.However, it will beapparent fromifiie Figurefi is a transverse sectionalview taken followin 'sp ifl l n that the Specific emhodir on the 'line6-5 of Figure 4 showing in detail 40 me 0! the P s lnvqntion describedthe manner in which the roller elements are 40 Q .toprovide a shockstrut of relatively simple conbe materially increased.

though being particmar-ly adaptable for m joumaled within the innerofthe cylindrical motive use, will ilndwide application and greatmembers, and v I utility in many and val-mus P fields? Figure 7 is asectional view taken on the line It. is a further object of the presentinvention of Figure 2 Illustrating the pivotal .m 45

, ing of oneof the front wheels. 1

struction which will be exceedingly strong and which Wm have the workingparts thereof effec With more particular reference to the draw ings thespecific embodiment of the in ention' tively protected from foreignmatter in order strut as wh 1e Wm V disclosed therein illustrates indetail one particuthe eflecuve'me of v o larly satisfactory use forshock struts of. the et another ob ect' of the present invention Pre$entinvemmnwhile Figures 2 and-3 h cozsists in the-.girovision of novelmeans for dr wings illustrate the improved shock strut used mounting theshoclcgstrunwhereby; n of the for providing independent suspensionforone o; n

' telescoping members is ently secured to the the front wheels of anautomotivevehicle, it will I support on which itis. unted. p f r beappreciated that the'invention may be satts- 55 ,befabparent thatfwhe nthe upperend ofthe tubularlrn frame member II). This frame member IIIhas secured thereto a. bracket II in which a front axle I2 is pivotallymounted for arcuate move- Substantially forment in a vertical plane.wardly of the bracket I l on the frame member ID is mounted a secondbracket ll in which is pivotally mounted a radius rod '5 which islikewise pivoted for vertical movement. The outer end Portions of theaxle I 2 and radius rod I5 are secured together by means ofa gussetplate l6 and have both their ends secured to a forging I! by means of asuitable transverse bolt l6.

This forging I1 is provided with a bore therethrough which providesmeans for mounting a conventional stub axle a conventional front wheel2|. is mounted in the forging I! by This stub axle 20 means of aconventional king pin 22 and preferably integrally formed therewith hasa steering arm 23 such as is conventional in the art.

The upper portion of the forging I1 is preformed to provide a socket 25which serves to receive and mount the lower end of the improvedshockstrut of the present invention. This socket 25 is adapted toreceive, and has mounted there: in a cylindrical tubular member 26 whichforms one of the primary elements of the shock strut constructionhereinafter described. The tubular member 26 is preferably permanentlysecured within the socket 25 and extends upwardly therefrom in adirection preferably substantially tangential to the arc of the circledescribed by the movement ofthe axle I2 about ,its pivot on the bodyframe. I

The extreme upper end of the tubular member 26 is preferably of slightlyreduced diameter and has a collar 21 permanently secured thereto whichserves to provide a seat for an annular frustoconical resilient stopmember 25, function of which will hereinafter become clear. Closelysurrounding the tubular member 26 at the base portion thereof is a shorttelescoping tubular member 30 which has its lower end hearing againstthemarginal edge of the socket 25 and which has permanently secured toits upper end an annular spring'r'eceiving collar 32 surrounding thetubular member 26 and permanently supported on thetubular member 30.

'A tubular member 35 having an outside diameter slightly less than theinternal diameter of the tubular memben l 6is, arranged in telescopingrelation thereto and-carries at its upper end a. cup-shaped cap 36preferably welded thereto and providing a seat for the head of an anchorbolt '31. The"frame portion ofgthe vehicle'to whichthei upper end =of ithe shock strut is adapted to be secured is provided'with a similaroppositely presenting cup-shaped cap member 39 which has a centralaperture permitting the passing of the bolt31 Anannulusll-of resilientmater 19-1, q 7 35 1 19 iii-S tr 81819111155 the bolt 3 |;and is seatedbetweengthe two facing cup shaped member s, d139,) t} ill therefore bolt,1 is tlghtenfed, er are be Secured concentrically to the tubular member35 and spaced therefrom is on which is'mounted the purpose and a inthesoeket an annular collar member 4| which has welded to the lower endthereof an annular spring receiving collar 42 which serves to receivethe upper end of a compression coil spring 43. The coll spring 43 issufllciently large in diameter to surround the tubular members 35 and26. as well as the resilient stop member 25. The lower end of thisspring element is preferably seated in the spring receiving collar 32carried by the tubular member 30 and described above.

The upper end of the tubular member 26 is preferably recessed to providespace for receiving annular packing 45 which will serve to effect asealing engagement between the tubular member 26 and the inner tubularmember 35. This packing 45 may be retained in place by means of thecollar 21 mounted on the upper end of the tubular member 26.

Throughout the area in which the tubular members 26 and, 35 are arrangedin telescoping relation, suitable means are carried-by one of thesemembers to provide for relatively frictionfree longitudinal movementthereof. While any suitable anti-friction devices may be interposedbetween the telescoping portions of these tubular members, it has beenfound preferable to provide a plurality of rollers carried by one of themem-' bers and serving to engage the adjacent surface of the other. Byway of illustration, Figures 4 to 6, inclusive, of the drawings show oneform of anti-friction means which has been found particularlysatisfactory for providing relatively friction-free longitudinalmovement of these tubular members with respect to each other. Arrangedone above the other in the inner tubular member 35 are a plurality ofdiametrically disposed shafts 50 which may be permanently secured to theinner tubular member 35 or may be journaled therein, as may be desired.In any event, however, it is desirable that these shafts 50 have theirends formed of a curvature lying substantially in the outer surface ofthe inner tubular member 35 in order to avoid any'undue abrasion of theinner surface of the adjacent tubular member 26. These shafts arepreferably arrangedin crossed axes relation to one another, in order toprovide maximum friction-free mountings of the tubular members withrespect to each other. While any one of a number of suitablearrangements will accomplish this desired result, I prefer to arrangethese shafts so that the axis of one roller is at about the axis of thethereof. Each of these shafts has in its axial central portion, andpreferably permanently secured theretofthe inner member of a raceway 5|whichhas a peripheral groove therearound adapted to receive a pluralityof ball bearings 52 which are confined by a groove in the innerperiphery of a roller 53. The roller 53 is preferably diametricallyarranged with respect to the tubular member 35 and has an outerperiphery adapted to engage the inner surface of the tubular memberadjacent rollers on either side 26. The roller 53 is preferably of anoutside i'diameter very slightly less thanthe internal Jf dlameter ofthe tubular member 26 in order that it will a and in proper axialalignment jprov ehfor relatively friction-free longitudinal serve tomaintain the tubular members 35 at all times and se two members withrespect to b i H f 'these roller elements may be moun ed within thetubular member 35 throughout the area which it engages the 90 degreeswith respect to inner surface of the tubular member 2t, there are.illustrated in Fig. 4 of the drawings four of these elements mounted forrotation on axes arranged at 90 degree angles with respect to eachother, the lower roller and the roller next to the top being arranged torotate on axes of rotation lying in the same plane, and the top rollerand the roller next to the bottom being arranged to rotate on axessubstantially at right angles to this plane.

From the foregoing it will be appreciated that when the shock strutconstruction of the present invention is subjected to bending stressessuch as are inherent in its normal operation, due to its mounting, thefriction-free mounting-of the telescoping tubular member due to thepresence of the rollers therein, will serve to facilitate longitudinalmovement of these members with respect to each other, irrespective ofthe bending stresses to which the strut as a whole may be subjected. Itwill be appreciated that the compression spring Q3 carried by themembers serves to resiliently control longitudinal movement of thesemembers with respect to each other and serves toprevent'shocks'transmitted to the wheel 2i from being transmitted to theframe of the automobile.

Further, it will" be apparent that the frustoconical resilient stopmember 28 will serve, when the members have been telescoped apredetermined amount, to provide resilient means to limit thetelescoping 'movement'of the members to a predetermined maximum. It willbe seen that, upon telescoping the tubular members 26 and 35, the upperannular end of the resilient element 28 will enter the annular recessbetween the collar M and the tubular member 35, thus providing apositive yet substantially resilient limit of predetermined telescopingmovement of these members.

Further, it will be appreciated that the resilient mounting of the uppertubular member 35 with respect to the frame, permits of accuratealignment of the tubular members with respect to each other. Further, itwill be seen that the axis of the shock strut as a whole is arrangedpreferably substantially tangential to the arc of the circle about whichthe axle member l2 and radius rod l5 swing, in order to reduce thebending stresses to which the strut as a whole is subjected to aminimum.

It will further be appreciated that the specific embodiment andapplication of the shock strut element herein'illustrated anddescribedis merely illustrative of one form which the generic inventive conceptpresented may take. Many and other further modifications falling withinthe scope of the subjoined claims will be apparent to those skilledinthe art.

What is claimed is:

1. A shock strut comprising a pair of tubular members adapted to bearranged in telescoping relation, rollers carried by one of said membersadapted to engage the surface of the other of said members to providefor friction-free relative longitudinal movement of said members, one ofsaid rollers being arranged on an axis at right angles to another ofsaid rollers, said rollers being of a diameter slightly less than thediameter of the member which they are adapted to engage.

2. A shockstrut comprising a pair of cylindrical members arranged intelescoping relation, a plurality of rollers arranged internally of theinner of said members, the diameter of said rollers being slightlygreater than said inner member and slightly less than the internaldiameter of said outer member.

3. A shock strut comprising a pair of cylindrical members arranged intelescoping relation, rollers diametrically arranged in the inner ofsaid cylindrical members adapted to engage the inner surface of theouter of said cylindrical members, the axis of some of the rollers beingtransverse to the axis of other of said rollers.

4. A shock strut comprising a pair of cylindrical members arranged intelescoping relation, a series of rollers diametrically disposed andjournalled in the inner of said members, adapted to engage theinner-surface of the outer of said members, adjacent rollers in saidseries having axes transverse to each other.

5. A shock strut for use in independent vehicle wheel suspensionscomprising a pair of tubular members arranged in telescoping relation,the inher of said tubular members having a plurality of rollersjournalled for rotation therein, said rollers having a, diameterslightly less than the inside diameter of said outer tubular member anddiametrically arranged with respect to said inner tubular member, theaxis of one of said rollers being arranged transverse to the axis ofanother of said rollers.

6. A shock strut for use in independent vehicle wheel suspensionscomprising a pair of tubular members arranged in telescoping relation,the inner of said tubular members having a plurality of rollersjournalled for rotationtherein, said side diameter of said inner tubularmember but less than the inside diameter of the outer tubular member,the peripheral surfaces of said rollers being complemental to theinterior surface of said outer tubular member, the axis of one of saidrollers being arranged transverse to the axis of another of saidrollers.

'7. A shock strut for use in independent vehicle wheel suspensionscomprising inner and outer tubular cylindrical members arranged intelescoping relation, the inner of said tubular members having anoutside diameter slightly less than the inside diameter of said outertubular member, the inner tubular member having slots in diametricallyopposite walls thereof, a roller having a diameter greater than theoutside diameter of said inner tubular member 'journalled for rotationtherein and having portions of its periphery projecting through saidslots and adapted to engage the inner surface of said outer tubularmember to provide for relatively friction-free telescoping movement ofone of said members with respect to the other.

8. A shock strut for use in independent vehicle wheel suspensionscomprising inner and outer tubular cylindrical members arranged intelescoping relation, the inner of said tubular members having anoutside diameter slightly less than the inside diameterof the outertubular member, the inner tubular member having pairs of slots in thewall thereof, one slot of each pair being on the diametrically oppositewall from the other slot of said pair, rollers journalled for rota-=tion in said inner tubular member, said rollers being of a diametergreater than the outside diameter of said inner tubular member andhaving portions of the peripheral surfaces thereof projecting throughsaid slots and adapted to engage the inner surface of said outer tubularmember, the axis of one of said rollers being arranged transverse to theaxis of another of said rollers. FRANK M. SMITH;

